Made an appointment to have it checked out. It's a 2019 GT1 and only have 400 miles on it but I noticed it 10 miles down the road after I bought it. Mine is a crackling/popping sound moreso than a rattle. Can't really hear it if the stereo is turned up or driving over 60. However when under 40 and volume down or off, it is noticeable. Worse when warmer out and open or closed sunshade makes no difference. When I just push on the headliner, it makes a crumpled up paper sound. Love everything else about the car but this will drive me crazy if not addressed.